1. Field of the Invention
The present invention generally concerns (i) motorcycle disk brakes and (ii) motorcycle belt and chain drives.
The present invention particularly concerns (i) a motorcycle disk brake rotor combined with (ii) a motorcycle belt (or chain) drive pulley, particularly so that (iii) a brake caliper engaging the disk rotor is located to the interior of the combination belt pulley and disk rotor. All elements may particularly be located to one side only of the motorcycle's rear wheel.
2. Description of the Prior Art
2.1 The Rear Wheel of a Belt Driven Motorcycle is Partially Obscured by Presence of a Drive Pulley and of a Disk Brake Each Upon Opposite Sides of the Wheel
Tens of thousands of custom wheels for full-size motorcycles--such as motorcycles of the manufacture of Harley-Davidson Corporation--have been sold in the United States at prices up to $1,000 U.S. per wheel, and more, since approximately 1984. These wheels are completely finished, often in brilliant polished chrome and/or polished billet aluminum in all exposed areas. They may additionally be patterned, such as with swirls and whorls. These wheels are presently widely available in the United States from over one dozen after-market manufactures.
Nonetheless to being (i) expensive, (ii) completely finished, and (iii) patterned, the custom wheels are commonly substantially obscured when mounted, as is most common, to belt and chain drive motorcycles. Such belt-drive motorcycles include, for example, virtually all those of the manufacture of the previously-mentioned Harley-Davidson Corporation in the period since about 1984. This is because these motorcycles have both (i) a drive pulley, and (ii) a disk brake rotor located concentrically with, and proximately to, the motorcycle's rear wheel each on an opposite side of the wheel. These round objects subtend a substantial portion of the diameter, and the central area, of the wheel, thus obscuring this area from a substantial part of the field of view of the wheel from all directions substantially orthogonal to the plane of the wheel.
Overwhelmingly most commonly, the (i) drive pulley is located on one side of the wheel, and the (ii) disk brake rotor on the other side, so that the function of each should not interfere with the function of the other. Ergo, both sides of the wheel are visually obscured, at least in part. It would be aesthetically very desirable if, commensurate with maintaining the full functionality of motorcycle (i) drive and (ii) braking, the magnitude of this masking from view of the motorcycle's rear wheel could be reduced, or eliminated--at least on one side of the wheel.
In certain rare "show" motorcycles a disk brake rotor and a drive pulley have previously been located on the same side of a motorcycle's rear wheel. In these instances the drive pulley has been substantially conventional while the disk brake rotor has been made in the shape of an annulus, or annular ring. This annulus has been disposed, as will seen to be importance as regards the distinction of the present invention, to the exterior of the drive pulley.
Because the drive pulley is--commensurate with its function of transmitting drive torque to the rear wheel of the motorcycle and with the requirement that the drive belt or chain should not be bent in too tight a radius--necessarily of a reasonable diameter, the previous disk rotor in the shape of an annulus has been very large, and ungainly appearing. It has typically been some ten to fifteen inches (10"-15") or more in diameter. By this construction a one side of the rear wheel is, however, unobstructed and fully exposed to view--an advantage that will also be seen to accrue to the present invention.
2.2 Each of the Belt Pulley, the Disk Brake Rotor, and the Disk Brake Caliper(s) of a Belt-Driven Disk-Braked Motorcycle Have Distinct Characteristics
The combination motorcycle belt drive pulley and disk brake rotor of the present invention will shortly be seem to "stand on its head", or "reverse", the previous orientation and relation of the (i) drive and (ii) brake parts located at the rear wheel of a motorcycle. Each of a new belt pulley component, a new disk brake rotor component, and a new disk brake caliper assembly will be seen to be different from, but roughly similarly visually appearing and functionally equivalent to, these same components and assemblies in the prior art. It is therefore worth a few sentences to consider the exact structures of these prior components.
A motorcycle belt pulley is normally affixed to the rear wheel of a motorcycle for rotation therewith, and about the rear axle shaft. The rear axle shaft is itself affixed at each of its two ends to the swing arm of the motorcycle suspension.
A conventional disk brake rotor is normally in the shape of a wide annular ring, or annulus, with a small central bore though which passes the axle. The annulus may be so wide that the disk brake rotor is sometimes not even regarded as being of this geometric form, being instead considered to be a circular plate with a central hole. This rotor is also affixed to the rear wheel of a motorcycle for rotation therewith.
Finally, the caliper of a motorcycle having disk brakes is commonly mounted to (i) the frame, or to a bracket that is in turn mounted to the frame, and (ii) the axle, of the motorcycle. The caliper has and defines a "U"-shaped yoke within which one or more pairs of pistons are opposed. Each piston moves a brake pad under force of hydraulic pressure towards a rotor that passes through, and that rotates within, the yoke. Compression on the rotor from opposed brake pads generates friction, braking the rotation of the motorcycle's wheel. The forces of the braking are ultimately transmitted to the (i) frame and (ii) axle.